Method of making debris-free plastic collating strip for nails

ABSTRACT

A fastener assembly is configured for use in an associated fastener driving tool for driving a fastener from the assembly into an associated substrate. The assembly includes a row of fasteners, each having a shank, arranged substantially parallel to each other. A collation system is formed from a plastic material that is molded onto and adhered to the fasteners. The plastic material is molded to define a collar portion substantially encircling the fastener shank and a connecting portion extending between and connecting adjacent collar potions. The plastic material is formulated from an adhesive polymer. When the fastener is driven from the driving tool, the collar portion remains adhered to the fastener such that the collar portion penetrates the substrate with the fastener.

BACKGROUND OF THE INVENTION

The present invention pertains to collated fasteners. More particularly,the present invention pertains to a collated nail strip formed with adebris-free plastic material for use in a fastener driving tool.

Fast-acting fastener driving tools are in widespread use in theconstruction industry. For use in these tools, the nails are assembledin strips that are inserted into a magazine of the tool. The strips areflat and the nails or other fasteners are held parallel to one another.The nails are assembled in a staggered or stepped manner such that themajor axis of the nail forms an angle to the longitudinal direction ofthe strip. In presently known collated nails, the angle is about 0degrees to 40 degrees and preferably between 15 degrees and 35 degrees.An in-depth discussion of such fasteners is provided in U.S. Pat. No.5,733,085, to Shida, which is incorporated herein by reference.

Presently known collated nails are assembled using tape strips or anextruded plastic material. The plastic (or polymer) in theplastic-formed strips is cooled and hardens to hold the nails in thestrip form for use in the tool. The tape strips are formed from a kraftpaper or other paperboard material having a plastic (polymer) adhesiveon a surface thereof that is heated on contact with hot nails and, as itcools, adheres to the nails.

Although tape strips have the advantage of minimizing the debris that isformed as the tool is actuated and the nails are driven into thematerial (typically wood) to be fastened, the plastic strips provideease of manufacture, especially for larger spaced nails. No materials,other than the nails and the plastic collating material are needed.

However, it has been noted that as the plastic collated nails are driveninto the workpiece, the plastic material shatters and separates from thenail shank. This can create loose debris at the worksite which canresult in housekeeping problems.

Accordingly, there is a need for a plastic collation system forstrip-formed fasteners that reduces the tendency for the plastic togenerate debris as the nail is driven into the workpiece. Desirably, thecollation system reduces the tendency for the nail strip to corrugate oradvance on itself in the tool magazine. More desirably, such a systemminimizes the amount that the strip can flex, and maximizes the adhesionof the plastic to the nail shanks.

BRIEF SUMMARY OF THE INVENTION

A fastener assembly is for use in an associated fastener driving toolfor driving a fastener from the assembly into an associated substrate,such as a wood substrate. The fastener assembly includes a row offasteners arranged substantially parallel to each other. Each fastenerhas a shank.

A collation system is formed from a plastic material that is molded ontoand adhered to the fasteners. The plastic material defines a collarportion that captures or at least substantially encircles the fastenershank and a connecting portion extending between and connecting adjacentcollar portions. The plastic material is formulated from an adhesivepolymer such as a polyolefin, a polyolefin blend, an epoxy or the like.When the fastener is driven from the driving tool, the collar portionremains adhered to the fastener such that the collar portion penetratesthe substrate with the fastener.

In a present strip, the polymer is a blend of polypropylene and a maleicanhydride modified polypropylene and adhesion is effected by preheatingthe fasteners prior to molding the plastic material to the fasteners. Apreferred preheating temperature is about 450° F. and preferably about450° F. to 600° F.

In the strip, the fasteners are parallel to one another and at an anglerelative to an axis of a selected one of the fasteners.

The connecting portion can be formed as a bridge and a rib in which thebridge and rib have a generally cruciform shape. The rib can be formedat an angle equal to the angle of the fasteners relative to the axis ofthe selected one of the fasteners. Alternately, the rib can be formed atan angle that is not equal to that of the fasteners relative to the axisof the axis of the selected one of the fasteners. Alternately still, theconnecting portion has an embossed pattern formed therein.

In a present strip, the collation system includes upper and lowerplastic moldings adhered to the fasteners. The upper and lower plasticmoldings are formed parallel to one another, with the upper moldingformed nearer to the head of the fastener and the lower molding formednearer to the tip of the fastener. The lower molding is formed on theshank of the fastener within the lower half and preferably within about½ inch of the tip of the fastener. The plastic molding can be formedhaving a taper to facilitate penetration into the substrate.

A method for making a fastener assembly includes the steps of arranginga plurality of fasteners in a row parallel to one another, preheatingthe plurality of fasteners to elevate the temperature of the fasteners,molding a polymer material onto the preheated fasteners and betweenadjacent fasteners to form a plastic collation having a collar thatcaptures or at least substantially encircles a shank of each fastenerand a connecting portion between adjacent fasteners and cooling thestrip to form the fastener assembly. The strip can then be post heattreated.

These and other features and advantages of the present invention will beapparent from the following detailed description, in conjunction withthe appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The benefits and advantages of the present invention will become morereadily apparent to those of ordinary skill in the relevant art afterreviewing the following detailed description and accompanying drawings,wherein:

FIG. 1 is a plan view of one embodiment of a nail strip or collationhaving a pair of plastic molded carrier strips;

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1;

FIG. 4 is an illustration similar to FIG. 2, showing a tapered collar;

FIGS. 5A and 5B illustrate portions of strips having angled ribs; and

FIGS. 6 and 6A illustrate an alternate bridge portion that is embossed,in which FIG. 6A is a cross-section taken along line 6A-6A of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in variousforms, there is shows in the drawings and will hereinafter be describeda presently preferred embodiment with the understanding that the presentdisclosure is to be considered an exemplification of the invention andis not intended to limit the invention to the specific embodimentillustrated.

It should be further understood that the title of this section of thisspecification, namely, “Detailed Description Of The Invention”, relatesto a requirement of the United States Patent Office, and does not imply,nor should be inferred to limit the subject matter disclosed herein.

Referring now to the figures and in particular to FIG. 1 there is showna nail strip 10 having a plastic collation system 12 embodying theprinciples of the present invention. In the illustrated strip 10, thenails 14 are positioned at an angle a of about 20 degrees to thetransverse direction of the strip 10; however, other angles a (includingzero degrees) are contemplated for use with the present invention.

As will be appreciated by those skilled in the art, the illustratednails 14 are full head nails, rather than D-head (or clipped head)nails. Accordingly, the nails 14 provide increased holdingcharacteristics (due to the increased surface area of the nail head H).However, it will also be appreciated that using full head H nails 14requires that the strip 10 is fabricated with a slightly greaterdistance d₁₄ between the (axes A₁₄ of the) nails 14 to accommodate thelarger nail heads H.

The nails 14 are collated and held to one another by the plasticcollation 12. The plastic collation 12 is molded to, over and around theshanks 16 of the nails 14, and connects each nail 14 to its adjacentnail or nails (that is, extends between the nails 14). The collation 12is formed as a contiguous molding (as indicated generally at 18) aroundand between the nails 14; nevertheless, for purposes of this disclosure,the molding 18 is viewed as having a collar portion 20, which is thatportion that encircles the nail shank 16, and a connecting portion 22,which is that portion that extends between and connects adjacent collarportions 20. In the nail strip 10 illustrated in FIG. 1, two plasticmoldings or collations are shown, namely an upper molding or collation12 a and a lower molding or collation 12 b, that are formed withstructure similar to one another. The following disclosure is applicablefor both of the moldings and are referred to collectively as molding orcollation 12.

The present nail collation 12 differs from previously known plasticcollations in a number of important aspects. First, rather than theplastic merely encircling and extending around and between the nails,the present collation uses a material that is molded and adheres to thenails 14. It has been found that plastic that is adhered to the nails,rather than merely molded around the nails is advantageous in that theplastic material tends to remain on the nail shank 16 during driving.That is, the collation 12 material is maintained on the shank 16 as thenail 14 penetrates the substrate and thus enters the substrate with thenail 14. Advantageously, much less debris is generated during driving ofa nail 14 from the present nail strip 10 compared to prior known nailstrips.

It will also be appreciated that the adhesion of the plastic material tothe nails 14 also has benefits vis-à-vis the rigidity of the nail strip10. That is, when the plastic merely encircles the nail shanks, theplastic can slip around the nail shanks. On the other hand, by adheringthe plastic molding 12 to the shanks 16, the nail strip 10 tends tobecome more rigid and is less likely to flex and to corrugate.

The material is an adhesive polymer, an epoxy or the like. The materialcan be, for example, an adhesive polyolefin such as a maleic anhydridemodified polyolefin, such as polypropylene, polyethylene or the like.The material can include a blend of a polyolefin and a modifiedpolyolefin, such as a blend of polypropylene and a maleic anhydridemodified polypropylene. One or more other resins can also be used, suchas a polyvinyl alcohol (PVA) based material, an ethylene vinyl alcohol(EVA) based material, an acrylonitrile butadiene styrene (ABS) basedmaterial, ionomers, methyl methacrylates and the like. Fillers can alsobe used as can blends of any of the materials, as suitable. Othermaterials will be recognized by those skilled in the art and are withinthe scope and spirit of the present invention.

A present plastic composition is a polypropylene resin that has beenmodified to enhance adhesion to surfaces, including metal surfaces. Apreferred resin is a maleic anhydride modified polypropylenecommercially available from Mitsui Chemicals America, Inc, of Rye Brook,N.Y., under the tradename ADMER® QF5512A.

It has been found that unexpectedly high levels of adhesion wereachieved using these modified resins when the resins were applied tonails 14 that were heated to elevated temperatures prior to applicationof the polymer (resin). Samples of nails were prepared by preheating thenails to a temperature of about 450° F. to about 600° F., and preferablyabout 500° F. to 550° F. and molding the maleic anhydride modifiedpolypropylene to the nails. These were tested against other molded nailstrip compositions, in which the molding was carried out with the nailsat ambient temperature and with the nails at elevated temperatures(shown as Cold and Hot under column listed as Nail Temp). Tests werealso carried out with strips that were postmolding heat treated (shownin columns identified as As Extruded and After 30 Min. Bake). That is,after the plastic material has been molded to the nails, the nail stripwas heated for a period of time (30 minutes) at a predeterminedtemperature. The results of the testing are shown in Table 1, below.

TABLE 1 PLASTIC ADHESION SHEAR STRENGTH OF VARIOUS PLASTIC NAILCOLLATIONS Plastic Adhesion Shear Strength (lbs) After 30 Bake PolymerMaterial Nail As Ex- Min. Temp Composition Tested Temp truded Bake (°F.) Polypropylene Current Cold 6.0 17.4 375 (PP) material Modified PP-Amplify GR Cold 6.5 48.4 300 anhydride 205 Cold 6.5 44.4 350 ModifiedPP- Amplify GR Cold 0.0 39.9 300 anhydride HDPE/anhydride MSI Cold 5.33.6 250 blend Cold 5.3 90.9 350 Hot 64.0 86.5 350 Modified PE- BynelCold 6.7 5.9 250 anhydride Cold 6.7 49.4 350 12% vinyl Elvax Cold 4.512.0 225 acetate copolymer Cold 4.5 15.9 350 EMMA Suryin Warm 0.0 51.2375 Copolymer (Zn) 9150 Modified PP- Tymor Cold 8.4 15.6 350 anhydrideCP97X110 Cold 8.4 88.0 375 Modified PP- Admer Cold 4.6 17.1 300anhydride QF551A Cold 4.6 28.0 350 Hot 71.0 210.4 350 Blend 75% CurrentCold 7.0 7.3 350 PP

In Table 1, the plastic adhesion shear strength (in pounds, lbs.) wasmeasured using a tensile testing device, by forcing the nails through aprecisely sized hole in a direction parallel to the nail axis A₁₄ andmeasuring the force required to separate the nail 14 from the plastic12. The nails that were pre-heated prior to molding were heated to atemperature of about 500° F. to 550° F., after which the plastic wasmolded to the nails. For the post heat treatment, the nails were heatedto the temperature shown for a period of about 30 minutes.

As can be seen from Table 1, the difference in plastic shear strengthbetween the non-pre-heated nails and the preheated nails is quitesignificant. For the present maleic anhydride modified polypropylene,the difference is a factor of over 15 (71.0 lbs./4.6 lbs.) without postmolding heat treatment. With post molding heat treatment, the shearstrength increased by a factor of almost 3 over the non-post heattreated (pre-heated) nails. The plastic shear strength was shown to beabout 71.0 lbs with pre-heating the nails prior to molding the plasticto the nails. In no case did a cold-applied plastic approach the shearstrength of the pre-heated nail strips.

It was observed that nails strips formed in accordance with the presentinvention exhibited a very limited amount of debris compared to knownplastic collations, principally because the plastic remained on the nailshank and penetrated the substrate (wood) with the nail. Moreover, itwas found that the debris that was generated was in the form of a finermaterial (smaller sized particles) so there was less of a housekeepingissue with the debris that was generated.

Debris was collected from samples of nails to determine the “debrisperformance” or reduction of debris generation of the present collationsystem. The amount of loose debris was measured by first weighing agiven collated nail strip consisting of 10 nails. The starting weight ofplastic was calculated by subtracting the weight of 10 uncollated nailsfrom this amount. The test nail strip was then fired into a substrate(e.g., wood board) surrounded by an enclosure to facilitate the captureand collection of the loose debris. The collected loose debris was thenweighed and divided by the original starting plastic amount to yield thepercent loose debris for a particular plastic collation material.

Table 2, below, summarizes the results obtained with selected three ofcollating plastic materials (a non-adhesive polypropylene material, anadhesive material in accordance with the present invention that wasformulated as a blend of 50 percent by weight polypropylene and 50percent by weight of the maleic anhydride modified polypropylene, and aformulation of 100 percent of the maleic anhydride modifiedpolypropylene). Firing tests were conducted in both pine and mediumdensity fibreboard (MDF) substrates.

TABLE 2 DEBRIS GENERATED FROM VARIOUS PLASTIC NAIL COLLATIONS % LooseDebris % Loose Debris Plastic collating material (Pine) (MDF)Non-adhesive polypropylene 86 91 Polypropylene/maleic anhydride 17 14modified polypropylene blend (50%/50% by weight) 100% maleic anhydridemodified 0 0 polypropylene,

It was also found that the nails carried the plastic into the wood andthat the plastic was embedded in the wood with the nail. In fact,surprisingly, this increased the nails' holding power in the wood. It isbelieved that this was due to the adhesive nature of the plastic as itembedded in the wood, in conjunction with the adhesion of the plastic tothe nail. That is, it is believed that the plastic (adhesive) flowedinto the wood structure and bonded with the wood structure, thusproviding even greater holding power.

Table 3 below shows the results of evaluations that were conducted tocompare the holding power or withdrawal strength of nails that were“fired” into wood from nail strips in accordance with the presentinvention to non-pre-heated polypropylene or control molded nail stripcollations. The withdrawal strengths were measured as the force (inlbs/in of withdrawal) required to pull the nail from the wood. Thevalues were normalized (e.g. calculated per inch of withdrawal) bydividing the force by the penetration depth.

TABLE 3 PENETRATION AND WITHDRAWAL STRENGTH OF NAILS CARRIED IN VARIOUSPLASTIC NAIL COLLATIONS Withdrawal Strength Plastic Sample StandingPenetration Ultimate (lbs./in. of Collation No. Ht. (in) (in) (lbs)withdrawal) Material 1 0.258 2.432 408.73 168.06 Tymor ™ 2 0.585 2.415372.28 154.14 Tymor ™ 3 0.618 2.382 150.06 63.00 Control 4 0.616 2.384150.93 63.31 Control 5 0.621 2.379 231.86 97.46 Admer ® 6 0.644 2.356127.87 54.27 Control

As can be seen from the data of Table 3, nail strips in accordance withthe present invention exhibited considerably higher withdrawal strengthscompared to non-adhered (control) nails. The control nails exhibitedwithdrawal strengths of about 54.3 to 63.3 lbs, whereas the preheatednails exhibited withdrawal strengths of about 97.5 to 168.1 lbs. In eachcase, the pre-heated nails required almost 54 percent greater force towithdraw or pull out the nails. At the same time, the nail penetrationwas essentially equal to that of the non-preheated nails. The Admer® andTymor™ materials are both maleic anhydride modified polypropylene.

In the present nail strips 10, the plastic is a uniform material that ismolded over the nail shanks 16 and between the nails 14. It will beappreciated that the plastic material can be a multi-part molding, inwhich discrete layers in the molding (collating) material are providedon the nails. In such a system, an adhesive can be applied or bonded tothe nails onto which a layer of a material with desired characteristics(e.g., a stiffer or more rigid material or a more impact resistantmaterial) is applied. Alternately, of course, a layered configurationcan be achieved using a coextrusion of two or more plastics.

Another aspect of the present nail strip 10 is the shape orconfiguration of the molding around and between the nails 14. That is,the shape of the collars 20 and the connecting portions 22. In a presentstrip 10, the collars 20 are formed as encircling elements that have agreater longitudinal or axial length at about a midpoint L_(20M) betweenthe connecting elements 22 (that is at about the midpoint of the circleinscribed by the nail), and dip to a smaller axial length at about theconnecting portions L_(20C).

The connecting portions 22 include a bridge 24 that extends from onecollar 20 a to the adjacent collar 20 b and is about the height H₂₂ ofthe collar 20 at the collar 20/connecting portion 22 juncture. Thebridge 24 is a relatively long, thin element that in fact “bridges” thetwo adjacent collars 20 a, 20 b. A rib 26 runs along the bridge 24 fromone collar 20 a to the next 20 b. The rib 26 is a cross-piece to thebridge 24 and has a low profile (e.g., is short) in the nail axialdirection or along the length of the nail (i.e., has a low thicknesst₂₆), but has a greater depth or width w₂₆ than the bridge 24. As seenin FIGS. 2 and 3, the cross-section of the bridge 24 and rib 26 iscruciform-shaped, and with the 26 rib serving as the cross-piece, therib 26 resides at about the middle of the bridge 24. A cross-sectiontaken through the nails 14 (see, FIG. 3) that provides a top or bottomview of the connecting portion 22 shows that the rib 26 actually has aconcave shape as it extends between the nails 14. Both the bridge 24 andthe rib 26 are formed having rounded ends, as indicated at 28.

As will be appreciated by those skilled in the art, when a nail 14 isdriven from the strip 10, it is the nail 14, the collar 20 and theconnecting portion 22 between the driven nail 14 and the next adjacentnail 14 b (see right-hand side of FIG. 1) that are separated from thestrip 10. Desirably, this entire “assembly” is driven into thesubstrate, and it will be understood that it is desirable to drive asmuch of the assembly as possible into the wood to, among other things,reduce the amount of debris that is generated.

To effect separation of the connecting portion 22, a notch 30 can beformed at the base or bottom 32 of the connecting portion 22 along adesired line of separation, or at the juncture of the connecting portionand the next adjacent nail. This provides a location at which the nail14, collar 20 and connecting portion 22, as a unit, separate from thestrip 10.

The connecting portion 22 provides the necessary rigidity to the strip10 that, in conjunction with the adhesive characteristics of theplastic, prevents corrugation of the strip 10. Nevertheless, even withthe increased adhesion and rigidity, that no significant increase inforce is needed to drive the nail 14 and separate the nail 14 from thestrip 10.

In a present nail strip 10, the upper and lower collations 12 a,b haveessentially equal dimensions. The collar 20 has a length L_(20M),L_(20C) of about 0.360 inches to 0.480 inches and a thickness t₂₀ ofabout 0.005 inches to 0.015. The bridge 24 has a length I₂₄ of about0.280 inches to 0.420 inches and a thickness t₂₄ of about 0.006 inchesto 0.014 inches and the rib 26 has a thickness t₂₆ of about 0.045 inchesto 0.060 inches and a width w₂₆ of about 0.087 inches to 0.128 inches.It will be appreciated that because the rib 26 has a concave shape, thewidth w₂₆ varies along the length of the rib 26.

Referring to FIG. 4, the collar 120 can be formed having a taper or athinned region 122 at the collar portion 124 closest to the tip 34 ofthe nail 14 or at the leading end of the collar 120. The collar 120expands or thickens toward the trailing end 126. It has been observedthat this taper 122 facilitates penetration of the nail 14 and plasticcollar portion 120 into the wood. The taper 122 is preferably formed atan angle β relative to the longitudinal axis A₁₄ of the nail 14, ofabout 0.5 degree to about 5.0 degrees, and most preferably about 1.0degrees. The taper 122 forms a wedge 128 that assists penetration of thenail 14 into the substrate and can further enhance the withdrawalresistance. It should, however, be recognized that the angle β cannot betoo great in that the wedge 128 could serve to split the wood.

It has also been observed that the location of the collar 20 on theshank 16 contributes to increasing the penetration of the nail 14 intothe wood. Specifically, it has been found that positioning the collar 20closer to the tip 34 of the nail 14 results in increased nailpenetration. It is believed that because the collar 20 (which is aninterference to penetration) is positioned closer to the nail tip 34,the greatest interference (that is as the collar 20 is entering thewood) is encountered while the impulse from the nail driving tool ishigh. Accordingly, the greatest resistance to penetration is overcomewhile the impulse from the tool is high, and, as such, penetration ofthe nail is greater when the collar 20 is positioned close to the nailtip 34 rather than farther back on the nail shank 16, near to the nailhead H.

An evaluation of the effect of the collar 20 position on the shank 16was conducted. Using a nail 14 that was 3 inches long and 0.131 nominaldiameter, with a collar length L_(20M) of 0.5 inches and a thickness t₂₀of about 0.020 inches and a collation material of maleic anhydridemodified polypropylene (Admer®) and a pneumatic driving force of 90 psi,it was found that a nail 14 having a collar 20 positioned 2.25 inchesfrom the tip 34 was driven (had a penetration of) 2.45 inches, a nail 14having a collar 20 positioned 1.5 inches from the tip 34 was driven 2.75inches, a nail 14 having a collar 20 positioned 0.5 inches from the tip34 was driven 2.975 inches, and a bare nail 14 was driven 2.925 inches

It will be appreciated by those skilled in the art that the use of aforward positioned collar 20 (or more generally a forwardly positionedcollation element or support) is not limited to use with a collated nailstrip 10. Rather, such an arrangement can be used with other stripformed fasteners and other strip-formed consumables.

FIGS. 5A and 5B illustrate an embodiment 210 in which the ribs 226 areformed at an angle γ and γ′ relative to an axis A₂₁₀ of the strip 10 (asopposed to the ribs 26 in the embodiment of FIG. 1 which are generallyparallel to the axis A₁₀).

FIGS. 6 and 6A illustrate an alternate embodiment of the plastic nailcollation 310 in which an embossed pattern 324 is formed in theconnecting portion 322 of the strip 310, rather than the bridge 24 andrib 26 configuration (of FIGS. 1-5). In the embossed pattern 324embodiment, a pattern of ribs 326 is formed in the connecting portion322 that can extend in one or both directions relative to a plane P₃₂₂that is defined by the connecting 322 portion extending between thecollars 320 (e.g., into or out of or both into and out of the plane P₃₂₂defined by the connecting portion 322 and the adjacent nails 14 a,b). Across-section of a one-directional embossing 324 is illustrated in FIG.6A. The embossing 324 serves to provide a three-dimensional structure,much like the bridges 24 and ribs 26, to enhance the rigidity of thestrip 310. In addition, it is anticipated that the embossing 324 canprovide the necessary rigidity and predictability in separation while atthe same time, reducing the amount of material needed to form the strip310. A rib 325 can be used with the embossed collation embodiment 310,as well. The embossing can also be formed in the collar. It will beappreciated by those skilled in the art from a review of the drawingsthat the present collation can be used with coiled nails (e.g., a rollernail strip) as well. In such an arrangement, the collation is formedwith a bridge connecting the collar portions, however, a reinforcing orstiffening element (e.g., rib) is not used so that the strip can becoiled.

All patents referred to herein, are incorporated herein by reference,whether or not specifically done so within the text of this disclosure.In the present disclosure, the words “a” or “an” are to be taken toinclude both the singular and the plural. Conversely, any reference toplural items shall, where appropriate, include the singular.

From the foregoing it will be observed that numerous modifications andvariations can be effectuated without departing from the true spirit andscope of the novel concepts of the present invention. It is to beunderstood that no limitation with respect to the specific embodimentsillustrated is intended or should be inferred. The disclosure isintended to cover by the appended claims all such modifications as fallwithin the scope of the claims.

1. A method for making a tape-less fastener assembly comprising thesteps of: arranging a plurality of fasteners in a row parallel to oneanother, each of the fasteners having a longitudinal axis; preheatingthe plurality of fasteners to elevate the temperature of the fasteners;molding a polymer material onto the preheated fasteners and betweenadjacent fasteners to form a first plastic molding having a collar fullyencircling a shank of each fastener and a connecting portion betweenadjacent fasteners and molding a polymer material onto the heatedfasteners and between adjacent fasteners to form a second plasticmolding having a collar fully encircling the shank of each fastener anda connecting portion extending between the collar portions of adjacentfasteners, one of first and second plastic moldings being an upperplastic molding and the other being a lower plastic molding, theconnecting portions extending parallel to and coplanar with a planedefined by the longitudinal axes of the fasteners; and cooling the stripto form the fastener assembly, wherein in the molding and cooling steps,the plastic molding adheres to the fasteners such that when a fasteneris driven into a substrate, debris generated from driving the fastenergenerates less than about 50 percent of the debris generated by drivinga non-pre-heated fastener into the substrate from a like assembly, andwherein the collar portion encircling the shank and substantially theentire connecting portion extending from the collar portion to about thenext subsequent collar portion penetrates the substrate with thefastener.
 2. The method in accordance with claim 1 wherein the polymeris a modified polypropylene.
 3. The method in accordance with claim 2wherein the polypropylene is a maleic anhydride modified polypropylene.4. The method in accordance with claim 1 wherein the connecting portionis formed having a bridge and a rib.
 5. The method in accordance withclaim 4 wherein the bridge and rib have a generally cruciform shape. 6.The method in accordance with claim 1 wherein the fasteners arepreheated to a temperature of at least about 450° F.
 7. The method inaccordance with claim 6 wherein the fasteners are preheated to atemperature of about 450° F. to 600° F.
 8. The method in accordance withclaim 1 wherein the polymer is a modified polyethylene.
 9. The method inaccordance with claim 8 wherein the polyethylene is a maleic anhydridemodified polyethylene.
 10. The method in accordance with claim 1including the step of forming a desired location of separation betweenadjacent fasteners on the strip.
 11. The method in accordance with claim1 wherein the step of arranging the plurality of fasteners includes thestep of staggering each fastener from each adjacent fastener to form anangle between each fastener and the strip.
 12. The method in accordancewith claim 11 wherein the angle is greater than zero.
 13. The method inaccordance with claim 12 wherein the angle is between about 20 degreesand about 30 degrees.
 14. The method in accordance with claim 13 whereinthe angle is about 20 degrees.
 15. The method in accordance with claim 1wherein the debris generated is less than about 25 percent of the debrisgenerated by driving a non-pre-heated fastener into the substrate from alike assembly.
 16. A method for making a tape-less fastener assemblycomprising the steps of: arranging a plurality of fasteners in a rowparallel to one another; preheating the plurality of fasteners toelevate the temperature of the fasteners; molding a polymer materialonto the preheated fasteners and between adjacent fasteners to form aplastic molding having a collar encircling a shank of each fastener anda connecting portion between adjacent fasteners; cooling the strip toform the fastener assembly; and post molding heat treating the fastenerassembly.